Light emitting apparatus, image pickup apparatus and control method therefor

Abstract

A light emitting apparatus that can obtain accurate color information including change of color information during luminescence. An information obtaining unit obtains status information on a status change of a light source in a luminescence time period of the light source. A determination unit determines color information of a light emitted from the light source in the luminescence time period based on the status information obtained by the information obtaining unit.

What is claimed is: 
     
       1. A light emitting apparatus comprising:
 a light source; 
 an information obtaining unit configured to obtain status information on a status change of said light source in a luminescence time period of said light source; 
 a determination unit configured to determine color information on a light emitted from said light source in the luminescence time period based on the status information obtained by said information obtaining unit; and 
 a storage unit configured to store a temperature change property of the color information on said light source, 
 wherein said determination unit calculates temperature information on said light source in the luminescence time period based on the status information obtained by said information obtaining unit, and determines the color information based on the calculated temperature information and the temperature change property of the color information stored in said storage unit. 
 
     
     
       2. The light emitting apparatus according to  claim 1 , wherein said storage unit stores a temperature change property of an amount of luminescence of said light source, and
 wherein said determination unit determines the color information based on the temperature change property of the amount of luminescence stored in said storage unit. 
 
     
     
       3. The light emitting apparatus according to  claim 2 , wherein said determination unit calculates a plurality of pieces of color information based on the temperature information and the temperature change property of the color information stored in said storage unit, and determines the color information by performing weighting on the calculated plurality of pieces of color information based on the temperature change property of the amount of luminescence stored in said storage unit. 
     
     
       4. A light emitting apparatus comprising:
 a light source; 
 an information obtaining unit configured to obtain status information on a status change of said light source in a luminescence time period of said light source; 
 a determination unit configured to determine color information on a light emitted from said light source in the luminescence time period based on the status information obtained by said information obtaining unit; and 
 a receiving unit configured to receive information on an exposure time period of an image pickup apparatus which is connected to the light emitting apparatus, 
 wherein said information obtaining unit obtains the status information for a plurality of times in a time period which overlaps with the exposure time period of the image pickup apparatus within the luminescence time period of said light source. 
 
     
     
       5. The light emitting apparatus according to  claim 1 , further comprising an output unit configured to output the color information to an external device. 
     
     
       6. The light emitting apparatus according to  claim 1 , wherein said information obtaining unit obtains temperature information on said light source as the status information. 
     
     
       7. The light emitting apparatus according to  claim 1 , wherein said information obtaining unit obtains drive current information and continued luminescence time period information on said light source as the status information. 
     
     
       8. The light emitting apparatus according to  claim 1 , wherein said information obtaining unit obtains a forward voltage of said light source as the status information. 
     
     
       9. The light emitting apparatus according to  claim 1 , wherein said light source is an LED. 
     
     
       10. An image pickup apparatus which is connected to a light emitting apparatus, wherein the light emitting apparatus has a light source, an information obtaining unit configured to obtain status information on a status change of said light source in a luminescence time period of said light source, and a determination unit configured to determine color information on a light emitted from the light source in the luminescence time period based on the status information obtained by said information obtaining unit, the image pickup apparatus comprising:
 an image pickup unit configured to obtain image data; and 
 an instruction unit configured to instruct, to the light emitting apparatus, supply of a drive current and a notification of the luminescence time period with respect to the light source. 
 
     
     
       11. A method for controlling an image pickup apparatus which is connected to a light emitting apparatus, wherein the light emitting apparatus has a light source, an information obtaining unit configured to obtain status information on a status change of said light source in a luminescence time period of said light source, and a determination unit configured to determine color information on a light emitted from said light source in the luminescence time period based on the status information obtained by said information obtaining unit, the method comprising:
 an image pickup step of obtaining image data; and 
 an instruction step of instructing, to the light emitting apparatus, supply of a drive current and a notification of the luminescence time period with respect to the light source. 
 
     
     
       12. The light emitting apparatus according to  claim 4 , further comprising an output unit configured to output the color information to an external device. 
     
     
       13. The light emitting apparatus according to  claim 4 , wherein said information obtaining unit obtains temperature information on said light source as the status information. 
     
     
       14. The light emitting apparatus according to  claim 4 , wherein said information obtaining unit obtains drive current information and continued luminescence time period information on said light source as the status information. 
     
     
       15. The light emitting apparatus according to  claim 4 , wherein said information obtaining unit obtains a forward voltage of said light source as the status information. 
     
     
       16. The light emitting apparatus according to  claim 4 , wherein said light source is an LED.